The present invention relates to a friction damper, which has been specifically designed for washing machines or the like.
As is known, the basket of a washing machine is conventionally suspended, at the top thereof, to the bearing framework of the washing machine by a pair of springs and is coupled, at the bottom thereof, to said washing machine bearing framework, by a pair of dampers.
Said dampers are designed to damp the oscillations affecting the washing machine basket during the operation of said washing machine, because of the turning movement of the basket and the uneven distribution of the linen being washed in the basket, i.e. about the axis of said basket.
The oscillations or vibrations of the washing machine basket have a greater amplitude at the start and end of the centrifuging operation of the washing machine, i.e. as the basket rotary speed variation is the greatest.
Conventional dampers used in conventional washing machine generally comprise a hollow shell and a rod which are coaxially arranged with respect to one another so as to form a telescopic construction.
The damping effect is usually derived from a pressing of the air held inside the assembly including said rod and shell, which air is pressed because of an overall reduction of the length of the shell rod.
Among the commercially available washing machine dampers, friction dampers are also known, i.e. dampers which, together with the damping effect provided by the mentioned pressing of the air held therein, further comprise a friction clamp, arranged between the inner surface of the shell and the outer surface of the rod.
Usually, such a friction clamp is affixed to the inner surface of the shell, the operating friction being generated between the clamp and outer surface of the rod.
Prior friction dampers, however, are affected by a quick wear of their rod, as well as a comparatively high operating noise.
The document FR-A-1322585 discloses a friction damper comprising friction clamps arranged between the inner surface of the damper shell and the outer surface of the damper rod.
The aim of the present invention is to overcome the above mentioned problem, by providing a friction damper, which has a comparatively small wear, and, accordingly, a much greater operating life with respect to conventional friction damper.
Within the scope of the above mentioned aim, a main object of the present invention is to provide such a friction damper, the components of which are affected by small mechanical stresses so as to prevent said damper from unnecessarily failing.
Yet another object of the present invention is to provide such a damper the operating noise of which is very reduced.
Yet another object of the present invention is to provide such a friction damper which is very reliable and safe in operation.
Yet another object of the present invention is to provide such a friction damper which can be made at a competitive cost.
According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become apparent hereinafter, are achieved by a friction damper, according to claim 1.